(i) In fig. 4.70, if , find the value of x.
Diagonal of trapezium divide each other proportiona
AO/OC=BO/OD
4/4X-2=x+1/2x+4
4x2-2x+4x-2=8x+16
4x2+2x-2-8x-16=0
4x2-6x-18=0
2(2x2-3x-9)=0
2x2-3x-9=0
2x2-6x+3x-9=0
2x(x-3)+3(x-3)=0
(x-3)(2x+3)=0
x-3=0
x=3
or,2x+3=0
2x=-3
x= -3/2
x=-3/2 is not possible
So x=3